During his journeys from Gastard to Corsham to attend school, his attention was probably much taken by the building of the Great Western Railway between 1836 and 1841. The building of the cutting and the bridge at Pound Pill would have enabled young John to watch the progress of the line and become well-versed in the working of stationary and moving steam engines.
In 1847 he joined Gilkes, Wilkes, Hopkins & Co – a firm of engineers in Middlesborough. Here, Fowler might well have remained had it not been for a chance visit to Ireland in 1849 during the time of the Irish potato famine. Irish agriculture was dependant on the potato crop whilst much of the land was uncultivated due to poor drainage.